:warning: THIS IS A EXPERIMENTAL DETECTION

This detection has been marked experimental by the Splunk Threat Research team. This means we have not been able to test, simulate, or build datasets for this detection. Use at your own risk. This analytic is NOT supported.

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Description

This search looks for child processes spawned by zoom.exe or zoom.us that has not previously been seen.

  • Type: Anomaly
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2020-05-20
  • Author: David Dorsey, Splunk
  • ID: e91bd102-d630-4e76-ab73-7e3ba22c5961

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1068 Exploitation for Privilege Escalation Privilege Escalation
Kill Chain Phase
  • Exploitation
NIST
  • DE.AE
CIS20
  • CIS 10
CVE
1
2
3
4
5
6
7
8
| tstats `security_content_summariesonly` min(_time) as firstTime values(Processes.parent_process_name) as parent_process_name values(Processes.parent_process_id) as parent_process_id values(Processes.process_name) as process_name values(Processes.process) as process from datamodel=Endpoint.Processes where (Processes.parent_process_name=zoom.exe OR Processes.parent_process_name=zoom.us) by Processes.process_id Processes.dest 
| `drop_dm_object_name(Processes)` 
| lookup zoom_first_time_child_process dest as dest process_name as process_name OUTPUT firstTimeSeen 
| where isnull(firstTimeSeen) OR firstTimeSeen > relative_time(now(), "`previously_seen_zoom_child_processes_window`") 
| `security_content_ctime(firstTime)` 
| table firstTime dest, process_id, process_name, parent_process_id, parent_process_name 
|`first_time_seen_child_process_of_zoom_filter`

Macros

The SPL above uses the following Macros:

:information_source: first_time_seen_child_process_of_zoom_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Lookups

The SPL above uses the following Lookups:

Required fields

List of fields required to use this analytic.

  • _time
  • Processes.parent_process_name
  • Processes.parent_process_id
  • Processes.process_name
  • Processes.process
  • Processes.parent_process_name
  • Processes.process_id
  • Processes.dest

How To Implement

You must be ingesting data that records process activity from your hosts to populate the Endpoint data model in the Processes node. You should run the baseline search Previously Seen Zoom Child Processes - Initial to build the initial table of child processes and hostnames for this search to work. You should also schedule at the same interval as this search the second baseline search Previously Seen Zoom Child Processes - Update to keep this table up to date and to age out old child processes. Please update the previously_seen_zoom_child_processes_window macro to adjust the time window.

Known False Positives

A new child process of zoom isn't malicious by that fact alone. Further investigation of the actions of the child process is needed to verify any malicious behavior is taken.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
64.0 80 80 Child process $process_name$ with $process_id$ spawned by zoom.exe or zoom.us which has not been previously on host $dest$

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

Test Dataset

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

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